import math

x1, y1, x2, y2 = map(float, input().split())

dist = math.sqrt((x1-x2) ** 2 + (y1-y2) ** 2)
print("{:.5f}".format(dist)) import math math x1, y1, x2, y2 = map(float, input().split()) x1 map(float, input().split()) map float input().split() ().split () input split y1 x2 y2 dist = math.sqrt((x1-x2) ** 2 + (y1-y2) ** 2) dist math.sqrt((x1-x2) ** 2 + (y1-y2) ** 2) math.sqrt math sqrt (x1-x2) ** 2 + (y1-y2) ** 2 (x1-x2) ** 2 x1-x2 x1 x2 2 (y1-y2) ** 2 y1-y2 y1 y2 2 print("{:.5f}".format(dist)) print "{:.5f}".format(dist) "{:.5f}".format "{:.5f}" format dist y1, x2, y2 = map(float, input().split()) map(float, input().split()) y1 x2, y2 = map(float, input().split()) map(float, input().split()) x2 x1, y1, x2, y2 = map(float, input().split()) map(float, input().split()) x1 dist = math.sqrt((x1-x2) ** 2 + (y1-y2) ** 2) math.sqrt((x1-x2) ** 2 + (y1-y2) ** 2) dist y2 = map(float, input().split()) map(float, input().split()) y2
import math

x1, y1, x2, y2 = map(float, input().split())

dist = math.sqrt((x1-x2) ** 2 + (y1-y2) ** 2)
print("{:.5f}".format(dist))
